Bridges as walls The biographer of Robert Moses, Robert A. Caro, refers to the bridges and underpasses of the famed New York State parkways. These bridges and underpasses are quite low, intentionally specified by Moses to allow only private cars to pass. All those who traveled by bus because they were poor or black or both were barred from the use and enjoyment of the parkland and its "public amenities" by the technical design of the bridges. Even at the time of Robert Moses, a political statement of the form "We don't want them blacks in our parks" would have been unacceptable in New York State. But a technological expression of the same prejudice appeared to be all right. Of course, to the public the intent of the design became evident only after it was executed, and then the bridges were there. Ursula M. Franklin, The Real World of Technology politicsclassracediscriminationurbanism
53. Main Gateways Problem: Any part of town—large or small—which is to be identified by its inhabitants as a precinct of some kind, will be reinforced, helped in its distinctness, marked, and made more vivid, if the paths which enter it are marked by gateways where they cross the boundary. Solution: Mark every boundary in the city which has important human meaning—the boundary of a building cluster, a neighborhood, a precinct—by great gateways where the major entering paths cross the boundary. Christopher Alexander, Murray Silverstein & Sara Ishikawa, A Pattern Language 112. Entrance Transition